NXP has launched a purpose-built system in package version of its S32 microcontroller range for automotive motor control designs.
The NXP S32M takes a 42V input for the motor control gate driver and in-package microcontroller die.
The design builds on the S12 MagniV to combine NXP’s motor control heritage and the software development benefits of the S32 platform. The system-in-package solution adds the power and analog functions as well as extensive software libraries required for motor control to NXP’s S32K microcontrollers for emerging software-defined electric vehicles.
The system in package combines the S32K1 ARM Cortex-M4 or Cortex-M7 K3 digital microcontroller die with memory options from 128KB to 1MB alongside a second custom die with the power, gate drivers, analog and wireless and CAN FD and LIN connectivity on the lead frame.
The controller is aimed at the emerging use of brushless direct current (BLDC) and permanent magnet synchronous (PMSM) motors for pumps, fans, sunroof and seat position, seat belt pretensioners and boot/trunk openers.
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“To drive a 12V motor control can require 50 to 60 components, and when you extend that to window lifters etc there are thousands of components just for motor control,” said Thomas Ensergueix, said Senior Director for Integrated Solutions Automotive Processing at NXP. “For the 12V motor control we previously used a 16bit MCU with extensions or M3 with DSP instructions.”
“EVs have a quieter power train which means all the small motors are more noticeable and more advanced algorithms can reduce the noise of the motors and drive them in higher efficiency mode to save energy.”
“One of the biggest challenges is managing the software and our approach is to have a consistent approach to the different functions, whether it’s crypto, safety or compute to make it easier when people transition to different architectures,” he said.
The gate driver chip is built in the SMARTMOS10 process and includes voltage regulators that take a 42V input from the car power bus to provide gate driver voltages for the motor control and 3.3V for the microcontrollers as well as a 12V output for other peripherals.
The S32M2 is a key step in the move to zonal architectures says NXP. OEMs can perform motor diagnostic tests, transmit data to the zonal controller and optimize for higher performance to improve efficiency further and lower audible noise in the final application, which improves occupant comfort. This can also use modern motor control algorithms that can be updated for quieter operation or more efficient power consumption such as FOC sensorless control, commutation control or current measurement modes. The algorithm optimisation can reduce noise by 10 to 15dB.
“It’s the spikes in torque that make the audible noise and the extra processing power can reduce the torque aberrations,” says Ensergueix.
Motors are used in a wide range of areas in the vehicle, including the parking pawl, a flexible tooth that slips into the gear to lock and even for steering wheel hand detection, where the integration is used the sensor rather that the motor control.
“By using NXP’s Model-Based Design Toolkit, automakers can start Simulink simulation early in the development cycle and map the model to the S32M2 hardware,” said Manuel Alves, Senior Vice President and General Manager of General Purpose and Integrated Solutions (GPIS), Automotive Processing, NXP. “Since this is a purely software-defined approach, automakers can optimize software re-use across the S32 vehicle compute platform, while benefiting from feature and performance enhancements.”
“Vehicle architectures are changing significantly to meet the requirements of a software-defined future,” said Dipti Vachani, SVP and GM, Automotive Line of Business at ARM. “By leveraging the efficient, low-power heritage of the ARM Cortex-M portfolio alongside ARM’s extensive software ecosystem, NXP’s S32M2 product is primed to power the safety-critical, real-time response requirements of edge applications in SDVs while enabling customers to focus their time on product differentiation rather than rewriting code.”
The system-in-package uses the S32K’s development processes certified to ISO 26262 for ASIL B functional safety with the S32 platform’s security subsystems (CSEc, HSE), and the S32K’s tools and software ecosystem.